Zooxanthellae -  

Calcification -this hard outer shell is made from the calcium and carbonate salts in seawater by a process called calcification.

Conveniently - this means conveniently there was food there.

Exoskeleton -one piece of coral can be home to many thousands of polyps each of which has a soft body protected by an exoskeleton 

Nutrients - Nutrients are something healthy in food etc.

Summary. 

Today we read about The Great barrier reef, Me and MIchael learnt about the corals in the reef such as Brain Coral, Staghorn coral , Cauliflower Coral , Elephant Ear Coral and table coral. We learnt that Corals have a clever system and they don’t have to rely on nutrients.

calcium builds up on rocks which forms the exoskeleton. Polyps are inside the exoskeleton ; they absorb sunlight and turn it into food. When the coral dies the exoskeleton stays there and new coral grow on top of it. 

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